Well strainer



March 1, 1938. D. MCDONALD 2,109,731

WELL STRAINER Original Filed April 1, 1956 I 2 Sheets-Sheet 1 Inventor Ill. m zz a, zaz

' Q By a; g Attorneys Patented Mar. l, 1938 UNITED STATES Application April 1, 1936, Serial No. 72,191 Renewed July 31, 1937 4 Claims. (01 ."166-5) The invention relates to strainers, and more particularly to a strainer for use at the lower end,

or at any other position in the casing of a well for straining water, oil or other fluids pumped or taken from the well free of foreign matter; and admitting gas through aperture from gas hearing formations at various depths.

A very important object of the present invention is to provide a strainer of the character and for the purpose mentioned which is not likely to become clogged, but which will operate with cf flciency at all times.

The invention, together with its objects and advantages, will be best understood from a study of the following description taken in connection with theaccompanying drawings, wherein:

Figure 1 is an elevational view illustrating the application of the invention to the casing of a water well;

Figure 2 is an elevational view of the strainer;

Fig. 3 is a longitudinal sectional view taken substantially on the line 3-3 of Figure 2;

Figure 4 is an elevational view of two of the sections of the strainer, with said sections being shown separated.

Figure 5 is a top plan view of one of the strainer sections.

' Referring to the drawings by reference numerals, it will be seen that the improved strainer is indicated generally by the reference numeral 5 and comprises a plurality of substantially aligned sections including a series of intermediate sections 6, a top section 1, and a bottom section 8.

The intermediate sections, 6 and the bottom section 8 are identical in construction in that each includes a substantially cylindrical lower body portion 9, a restricted intermediate portion Ill, and a cylindrical end portion ll of materially less diameter than the end portion 9.

Also formed integral with the "parts III and II of each of said sections 6 and I are ribs l2 formed adjacent their lower ends with shoulders l3.

The top section 1 is of cylindrical form and of uniform diameter throughout its length.

As clearly shown, the ends I l of the sections extend into the ends 9 of the next adjacent section and the portions 9 of the sections are welded or otherwise secured to the edges of the ribs l2 with the free ends of the largest portions 9 of sections 6 and 1 abutting the shoulders IS.

The top section 'I is provided at its free upper end with either internal or external threads ll through the medium of which said section is PATENT OFFICE? 1 .threadedly engaged with the lower 'end of the' well casing l5 as suggested inFlgure 1. v The lower section 8 at, its lower ,edge is-provided with either internal or. external threads :16, through the medium-of which said section is 5 threadedly engaged with the threaded stem of a base or a foundation. disposed in alignment with the lower end of the well. casing and resting on the stratum of clay I 8, or engaged with the threaded end of the well casing, tobe extended below the bottom end of said strainer to any depth.

As shown in Figure 1, the strainer 5 is so disposed at the lower end of the well casing l5 as to extend below the several earth strata. A and B \into the fine sand or gravel stratum l9 found in 1 sand water bearing or other formations.

It will thus be seen that with the sections or units of the strainer thus assembled there is provided a strainer having at intervals throughout its length inlet openings 20' with a circular series of passages 20 associated with each series of inlet openings'to the end that the water and foreign matter drawn into the strainer will be forced to flow in an inward and upward direction through the strainer. Thus with thisstrainer while the water will travel in and rise upward to its highest level above the strainer the gravel or the foreign matter will not. Hence, it is possible that a strainer of this character will permit use of a very fine gravel in a gravel wall, gravel treat- 30 ed or gravel packed well, and retain all gravel used in such treatment on the outside of the strainer where it belongs, still retaining the extra large inlet areas of the strainer. Further, by such a construction and arrangement, the 5 strainer will tend to prevent gravel or other solid matter from ever entering the well to the end that the possibility of the strainer ever becoming clogged is practically obviated.

It will be further understood that the strainer embodying the features of the present invention may be constructed of fabricatedmaterials, or it may be cast. Further, the strainer can be cheaply manufactured of metals best suited to resist damaging effect of chemicals held in solution in water to be handled, and that the strainer may be used with all types of well casings, and may be installed without trouble, and at a much greater depth than is feasible with concrete strainers now generally employed.

Having thus described the invention, what is claimed as new is:

1. A strainer for wells comprising an elongated substantially tubular structure adapted to be connected at various positions in a well cas- 2 ing, said structure being provided at intervals with inlet openings and passages admitting through apertures extending inwardly from said openings parallel to the axis of the strainer, said strainer consisting of a plurality of identical cylindrical sections each having a relatively large cylindrical end, and a relatively small cylindrical end, with the smaller end of each section fitting in the larger-end of the next adjacent section, and all said sections being hollow and open at their respective opposite ends and means on the smaller ends of said sections engaging the larger ends of adjacent sections to maintain the larger sections in spaced longitudinal relation with respect to eachother and in spaced concentric relation with respect to the smaller sections.

' 2. In a strainer for wells, a plurality of substantially identical intermediate sections and top and bottom end sections, said intermediate sections and said bottom section each including a cylindrical body open atits ends and having a cylindrical end of relatively large diameter, a second cylindrical end of relatively small diameter fitting within the largest end of the next adjacent section and a constricted intermediate portion connecting the ends of said sections, longitudinally extending spacing ribs formed on the reduced cylindrical end of each intermediate section, said ribs being reduced in width adjacent the upper portion thereof to provide a shoulder on each rib for supporting the lower edge of the next adjacent section to maintain the large cylindrical sections in spaced longitudinal relation.

3. A strainer for wells comprising a plurality of elongated hollow sections, each section having one end thereof of smaller outer dimension than the other end, the smaller end being extended into the larger end of the adjacent section for a material portionof its length, means centering said smaller end in said larger end, and meansv to secure 'said centering means integrally to said sections with the surfaces ,of said ends spaced apart, thus providing passages extending vertically between said ends for fluid, the outer surfaces of said larger ends being aligned longitudinally and of approximately uniform diameter.

4. A well strainer made up of interfitting sections including a lower section and an upper section, the outer surface of said sections being of approximately the same dimensions and substantially parallel with the axis of the strainer, the upper end of the lower section fitting freely within the lower end of the upper section, said upper end being smaller than the lower end of said upper section to provide a vertical passage between the interfitting ends for fluid moving upwardly into said strainer, and means to secure said sections together and also to space said upper end uniformly within the lower end ofsaid upper section.

DAVID L. MCDONALD. 

